farmakokinees

Farmakokinees, also known as pharmacokinetics, is the branch of pharmacology that studies the time course of a drug in the body. It describes how the body absorbs, distributes, metabolizes, and eliminates a drug (the ADME framework).

Absorption describes entry into the systemic circulation after administration, influenced by route, formulation, and physiological factors; distribution describes movement into tissues and fluids, governed by blood flow and tissue binding; metabolism converts drugs to more water-soluble compounds, mainly in the liver; excretion removes substances via kidneys, bile, or exhalation.

Key parameters include Cmax (peak plasma concentration), Tmax (time to Cmax), AUC (area under the concentration–time curve), half-life (t1/2), clearance, and volume of distribution. These are estimated from concentration–time data using non-compartmental or compartmental models, and can inform dose regimens.

Pharmacokinetics guides dosing, formulation development, and therapeutic drug monitoring. It is affected by age, organ function, genetics, disease states, interactions with other drugs, and external factors such as food.

Advances in modeling and simulation, including population PK and PK‑PD integration, help tailor treatments and optimize regimens across patient groups. The field supports safer and more effective use of medicines by predicting how different factors alter drug exposure and response.